[jetcaster] Fixed the laggy scrolling (#614)

* Fixed the laggy scrolling Extracted the Category podcasts and Episode lists to separate composables * Addressed review comments. * Remove extra spaces

Author: kedar1607

Jetcaster/app/src/main/java/com/example/jetcaster/ui/home/category/PodcastCategory.kt

@@ -19,6 +19,7 @@ package com.example.jetcaster.ui.home.category
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
@@ -67,6 +68,7 @@ import androidx.lifecycle.viewmodel.compose.viewModel
 import coil.compose.rememberImagePainter
 import com.example.jetcaster.R
 import com.example.jetcaster.data.Episode
+import com.example.jetcaster.data.EpisodeToPodcast
 import com.example.jetcaster.data.Podcast
 import com.example.jetcaster.data.PodcastWithExtraInfo
 import com.example.jetcaster.ui.home.PreviewEpisodes
@@ -98,20 +100,39 @@ fun PodcastCategory(
  /**
  * TODO: reset scroll position when category changes
  */
- LazyColumn(
- modifier = modifier,
+ Column(modifier = modifier) {
+ CategoryPodcasts(viewState.topPodcasts, viewModel)
+ EpisodeList(viewState.episodes)
+ }
+}
+
+@Composable
+private fun CategoryPodcasts(
+ topPodcasts: List<PodcastWithExtraInfo>,
+ viewModel: PodcastCategoryViewModel
+) {
+ LazyRow(
  contentPadding = PaddingValues(0.dp),
- horizontalAlignment = Alignment.Start
+ horizontalArrangement = Arrangement.Start
  ) {
  item {
  CategoryPodcastRow(
- podcasts = viewState.topPodcasts,
+ podcasts = topPodcasts,
  onTogglePodcastFollowed = viewModel::onTogglePodcastFollowed,
  modifier = Modifier.fillParentMaxWidth()
  )
  }
+ }
+}
+
+@Composable
+private fun EpisodeList(episodes: List<EpisodeToPodcast>) {
+ LazyColumn(
+ contentPadding = PaddingValues(0.dp),
+ verticalArrangement = Arrangement.Center
+ ) {
 
- items(viewState.episodes, key = { it.episode.uri }) { item ->
+ items(episodes, key = { it.episode.uri }) { item ->
  EpisodeListItem(
  episode = item.episode,
  podcast = item.podcast,